1. Field of Invention
The invention relates generally to controlling parameters within a shipping container and more particularly, to a device (also known as a “unit” or a “module device”), system, and method for controlling cargo (also referred to as “freight”) parameters in a microenvironment of a shipping container during transit.
2. Description of Related Art
A shipping container is a container with strength suitable to withstand shipment, storage, and handling. One type of shipping container in the transportation of cargo is called a reefer. The cargo in reefers could be any type of cargo requiring climate control and/or protection from “hot” or “cold” conditions. A reefer is a term of art that means a refrigeration unit married to an insulated box for the carriage of cargo such as a refrigerated container, refrigerated trailer, refrigerated boxcar, refrigerated air cargo container, refrigerated truck, etc. The refrigeration unit controls the temperature of the conditioned air either delivered to and/or returning from the cargo space. Controlling is the sensing and transmitting of the temperature and other conditions to the reefer unit's microprocessor for the regulation of the conditioned air either delivered to and/or returning from the cargo space.
An advantage of using a multimodal reefer to ship cargo is that the reefer does not require any handling of the cargo itself when changing modes of transportation. For example, when transferring cargo between a train, a ship, a truck, and/or an aircraft, the reefer reduces damage and loss, allows cargo to be transported faster, and improves security.
A problem with conventional reefers is precisely controlling the temperature, humidity, oxygen, carbon dioxide, ozone and other constituents of the air and cargo in various locations within (e.g., inside) the cargo space during transit.
U.S. Pat. No. 6,862,499 issued to Cretella et al. is directed to regulating the conditioned space of an environment-controlled transport unit by identifying the product being conveyed as cargo in the conditioned space of a transport unit. A user can identify the type of cargo by selecting it from a menu of cargo identifiers. Once the type of cargo is identified, an environment control system retrieves from memory environment-control parameters as a function of the identified cargo, and regulates the environment of the conditioned space based upon the environment-control parameters. A remote database provides a control unit with data concerning various products and their associated environment control parameters. One or more sensors located inside the refrigeration unit provide information to the control unit about the environmental conditions either returning from (“return air”) and/or entering (“supply air”) into the cargo space, such as temperature and humidity. The control unit regulates the conditioned air supplied to cargo space by selecting the type of cargo and retrieving cargo controlling parameters from the remote database without external input. The control unit does not regulate microenvironments within the cargo space.
U.S. Pat. No. 6,679,071 issued to Storey et al. is directed to a temperature responsive refrigerated transport container having a self-contained refrigeration plant in which a short range radio transmits a sensed temperature to a remote operator panel using an identity code with the panel controlling the plant via a radio transmitter using an operating signal generated at the panel. A communications interface remotely monitors and/or controls the refrigeration container operating conditions. Monitoring is the sensing and recordation of conditioned air. The controlling and monitoring of the refrigeration transport container may be carried out from a remote central bureau.
However, each of these conventional reefer devices falls short because they do not allow users to measure reefer parameters, or cargo parameters, during transit. For example, these conventional devices do not establish communication throughout the entire time in transport from origin to destination and do not control the condition of the cargo itself.